The goal of this project is to investigate the phonological processing abilities of children with specific language impairments (SLI) and children developing language normally (NL). Previous research has shown that children with SLI are less accurate than children with NL when repeating nonsense words. While this has traditionally been interpreted as a deficit in the phonological loop component of working memory, there is also evidence that children with SLI experience deficits in a number of other phonological processes that support accurate repetition, including speech perception, phonological encoding, and phonological assembly (articulatory planning). In spite of these deficits, the patterns of sensitivity to phonological materials in children with SLI are similar to those shown in children with NL, albeit with children with SLI exhibiting reduced levels of performance. However, these sensitivities are mediated by frequency effects. That is, children with SLI show subtle deficits (or even no deficits) when tested with frequently occurring, familiar items. But when tested with infrequent or unfamiliar items, children with SLI show an inordinate level of degraded performance. Therefore, this series of studies examines how the frequency or familiarity of stimulus items interacts with phonological processing in children with SLI and NL. Specifically, the proposed studies are designed to investigate familiarity or frequency effects in speech perception and phonological encoding using a categorical perception and memory span task, respectively, and to examine the robustness with which phonological units are assembled (or possibly stored) by using a phonological priming paradigm.